body {
    font-family: Arial, sans-serif;
    margin: 20px;
}
h1 {
    color: #2c3e50;
}
.message {
    color: #27ae60;
    font-weight: bold;
}
.error {
    color: #e74c3c;
    font-weight: bold;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}
th, td {
    padding: 10px;
    border: 1px solid #ddd;
    text-align: center;
}
th {
    background-color: #3498db;
    color: white;
}
tr:nth-child(even) {
    background-color: #f9f9f9;
}
.add-form {
    margin: 20px 0;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background-color: #ecf0f1;
}
.form-group {
    margin-bottom: 15px;
}
label {
    display: inline-block;
    width: 100px;
    margin-right: 10px;
    color: #2c3e50;
}
input, select {
    padding: 5px;
    border: 1px solid #ddd;
    border-radius: 3px;
}
.delete-btn, .btn-delete {
    background-color: #e67e22;
    color: white;
    border: none;
    padding: 5px 10px;
    cursor: pointer;
    border-radius: 3px;
}
.delete-btn:hover, .btn-delete:hover {
    background-color: #d35400;
}
.back-btn, .btn-add {
    background-color: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 3px;
    padding: 8px 15px;
    display: inline-block;
    border: none;
    cursor: pointer;
}
.back-btn:hover, .btn-add:hover {
    background-color: #2980b9;
}
.btn {
    display: inline-block;
    padding: 6px 12px;
    margin-bottom: 0;
    font-size: 14px;
    font-weight: 400;
    line-height: 1.42857143;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    background-image: none;
    border: 1px solid transparent;
    border-radius: 4px;
}
.btn-add {
    background-color: #3498db;
    color: white;
    border-color: #2980b9;
}
.btn-add:hover {
    background-color: #2980b9;
}
.btn-delete {
    background-color: #e67e22;
    color: white;
    border-color: #d35400;
}
.btn-delete:hover {
    background-color: #d35400;
}